The present invention relates to a means for ensuring the proper assembly of a rotary type railway car coupler and more particularly to a specific structure which will not permit the yoke collar to be assembled 180.degree. out of phase with the proper orientation.
The railway car coupler of the present invention is generally applied to railway cars used for rotary dump service where the rotating car remains coupled to the immediately adjacent cars. The coupler is mounted on a railway car which is designed to be unloaded by individually clamping the car body in a device which rotates the entire car including trucks about a longitudinal axis near the normal axis of the couplers until the car is unloaded, and then rotates the empty car back to its normal position. During this operation the adjacent cars remain stationary in a normal upright position.
The cars provided for this application are generally equipped with a rotary type coupler at one end and a standard stationary coupler at the other end. The train is then assembled so that each rotary type coupler is coupled to a standard stationary coupler. Each rotary coupler must therefore be capable of rotating with respect to the car on which it is mounted.
The rotary type coupler includes a shank which is attached to the car by being pinned to a yoke collar associated with a draft gear. The yoke collar bears against a yoke during a draft condition. The butt end of the shank bears against a follower located in the center sill during a buff condition. Therefore, when the car is rotated for unloading, the coupler and its shank, the connecting pin and yoke collar all remain stationary while the yoke, follower, and draft gear all rotate with the car.
In the normal running position of the coupler, the connecting pin is held in a vertical position. The yoke collar has an opening which receives the pin and that opening is restricted at its opposite end by a pin seat flange. When the coupler is properly assembled, the pin seat flange is at the bottom of the yoke collar, and therefore, the pin is held oriented in its correct position. In this proper position the collar is designed to assume the stresses imposed thereon by the pin during a draft condition.
In order to assemble this coupler, however, the yoke collar must be inserted in the yoke with the pin seat flange up. Then the coupler shank is inserted, also inverted with respect to the car, through the end of the yoke and into the yoke collar until the hole in the shank aligns with the opening in the yoke collar. The connecting pin is then inserted from the bottom, and the coupler, connecting pin and yoke collar are rotated 180.degree. so that the coupler is in its running position and the pin is resting on the pin seat flange which is now properly at the bottom of the yoke collar.
Occasionally, however, after the yoke collar has been properly inserted in the yoke with the pin seat flange up which is necessary to accept the pin from below, the coupler shank is incorrectly inserted in its normal running position. The pin is then inserted from below, and a cover plate is fixed in place. Under these conditions, the coupler, of course, is not rotated because it is already in its proper position.
When the coupler has been assembled as above, the pin seat flange is at the top of the yoke collar, and the pin is free to fall from its proper position through the opening in the bottom of the yoke and rest against the cover plate.
This improper positioning of the connecting pin greatly reduces, and occasionally completely eliminates, the bearing area of the pin on the upper portion of the yoke collar. Thus during running operation, the entire draft load is concentrated at the bottom of the yoke collar, often resulting in fracture of the yoke collar and severe damage to the coupler shank. Furthermore, this improper positioning of the connecting pin would seriously affect the operation of the connection when the car is rotated for unloading.
It is a primary object of the present invention to provide a rotary type railway car coupler constructed and arranged to overcome the difficulties encountered heretofore and thereby improve the service life and reliable operation thereof.
According to the present invention this is accomplished by providing a means for ensuring that the shank and yoke collar are assembled in the proper orientation with respect to one another. In one embodiment of the invention, a projection is provided on the inside of the yoke collar and a corresponding groove is formed in the coupler shank so that the shank and yoke collar must be assembled with the pin seat flange located at the bottom of the yoke collar when the coupler is in its running position. This structure precludes the misapplication of the coupler shank by rejecting the shank if it is not properly oriented with respect to the yoke collar and assures that the coupler will always be assembled so that the pin seat flange is at the bottom of the yoke collar.